Pluto's Dark Side
Long-awaited images from the far side of the dwarf planet show Pluto in a new light. Among other things, evidence of liquid water is accumulating on the frigid world.
When NASA's New Horizons spacecraft flew past Pluto in July 2015, its images came as a big surprise. What was seen was a much more dynamic and diverse world than scientists had previously dreamed of. On Pluto, not only do cliffs of frozen nitrogen rise like rugged fjords, but also blocks of methane ice, some as tall as skyscrapers. The dwarf planet's surface also has cracks deeper than the Grand Canyon, while some ice volcanoes dwarf Mount Everest.
And then, of course, there's the huge heart-shaped area on one side of the dwarf planet that delighted space enthusiasts in the days after New Horizons' flyby. "I expected Pluto to be a scientist's paradise," says New Horizons team member Leslie Young of the Southwest Research Institute in Boulder, Colorado. "But who knew he was so beautiful?"
It's been almost five years since Pluto was first seen, but researchers like Young have since seen new images of the distant world…